Nearly four miles under the Pacific Ocean, in a place darker and colder than almost anywhere else on Earth, a robotic vehicle spotted something odd stuck to a rock. Small, jet-black spheres. Nobody on the research team knew what they were looking at.
That moment turned into one of the more unexpected biology stories of the decade. According to the study, ‘Flatworm cocoons in the abyss: same plan under pressure,’ published in the journal Biology Letters, those black spheres turned out to be egg capsules, and inside them were flatworms living deeper than any free-living flatworm humans have ever documented.
